Compressor



T. H. ALFREDS.

COMPRESSOR.

APPLICATION FIL ED JAN. 19, l9l7- Patented Nov. 18, 1919.

I 2 SHEETSSHEET L Jim T. H. ALFREDS.

COMPRESSOR.

APPLICATION FILED JAN. 19. 1911.

1,322,277. Patented Nov, 18, 1919' 2 SHEETSSHEET 2 Jail/@7275? a orzyfiffi UNITED STATES OFFICE.

TORRIS EH. ALFREDS, OF CHICAGO, ILLINOIS, ASSIGNOR T0 FRED W. WOLF, OF CHICAGO, ILLINOIS.

COMPRESSOR.

Specification of Letters Patent.

Patented Nov. 18, 1919.

Application filed January 19, 1917. Serial No. 143,344.

To all whom it may concern:

Be it known that I, TORRIS H. ALFREDS, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Compressors; and I do hereby declare that the following is a. full, clear, and exact description thereof, reference being had to the accompanying drawings. and to the letters of reference marked thereon, which form a part of this specification.

i This invention relates to improvements in compressors, and consists of the matters hereinafter referred to and more particularly pointed out in the appended claims.

The object of the invention is to provide a valveless compressor, that is to say, a com pressor in which the inlet and exhaust to and from the cylinder is controlled by the piston itself, without the use of separate and independent valve mechanism. The advantages of such a compressor will be apparent to those familiar with the art, and willbe pointed out more particularly as I proceed with my specification.

In the drawings:

Figure 1 is a view representing a longitudinal section through my improved compressor. in the vertical plane of the central axes of the cylinders.

Fig. 2 is'a view representing a transverse vertical section through the compressor in a plane indicated by the line 2 2 of Fig. 1.

Fig. 3 represents a side elevation of the compressor on asomewhat smaller scale than that of 1 and 2.

Fig. 4 is a detail, sectional view through one of the cylinders, showing the piston in a somewhat different position from that shown in Fig. 1.

Fig. 5 is a view representing a transverse section through Fig. 4, in a plane indicated by the line 5-5 of Fig. 4.

Fig. 6 represents a horizontal sectional view through one of the cylinders in a plane indicated by the line 66 of Fig. 4.

Referring now to that embodiment of my invention illustrated in the accompanying drawings 11 indicates. as a whole, the casing of the compressor. Said casing consists generally of a cylindrical shell 12 and of two end members or heads 13, 13 which close the ends with the cylinders beyond the planes of the plates 13*. The plates are secured to the ends of the cylindrical shell 12 by lag screws or any other means.

15 indicates the driving shaft of the compressor. Said shaft is mounted in the shell intermediate the ends of the shell (as shown, half way between said ends) and is located in a horizontal )lane with the longitudinal central axis intersecting the line of the axes of the cylinders, 14. 14. Said shaft has bearing in plates 16. 17 fixed to the sides of the shell 12 at suitable. alined bearing openings formed in said shell.

The plate 16 has a bearing sleeve 16 made integral with it and supported by means of connecting radial ribs 16". Said sleeve provides bearing for one end of the shaft 15, but is spaced somewhat from the plate 16 to allow room for an end thrust disk 15 fixed to the end of the shaft. and acting to distribute the thrust of the shaft over a large surface of the plate 16. The plate 1 7 has a journal box 18 made integral with it and projecting from its outer face. nular flange 19 on its inner face provides a stuffing box which is closed by a gland20 mounted on the shaft 15. Contractile coil springs 21 connecting a radial flange 22 of the said gland with fixed parts on the hearing plate 17, yieldingly hold the packingwithin the stuffing box, and pins or studs 23 extending inwardly from said plate and engaged in suitable apertures in said flange 22 hold the gland against rotation. A driving pulley 24 is fixed to the driving shaft adjacent to the journal box 18.

25 indicates what is familiarly known as a Scotch yoke. mounted in vertical plane Thus the rotation of the shaft 15 produces a reciprocatpry movement of the yoke and,

.in consequence, the required reciprocation respectively. The block 27 is provided at its ends with vertical ribs which have guiding grooves or ways formed on the inner faces of the vertical members of the U-.

plates of the yoke.

In the wall of each cyinder let, preferably on the bottom side, is provided a longitudinally extending conduit or passageway which opens at its ends into the interior of the cylinder by means of ports 36 and 37. These ports are made inthe form of long, narrow slots which extend transversely of the cylinder axis. The port- 36 opens into the cylinder at a line spaced from the inner end of the cylinder while the port 37 opens into the cylinder at a line closely adjacent to the outer end or head of the cylinder. A

third and smaller port 38 connects the pars sageway 35 with the interior of the cylinder at a point near the port 37,. but spaced a greater distance from the cylinder head than said port 37. Said port 38 is adapted to re ister with an inclined assa ewa 26*- which opens at one end through the end of the piston, and opens at the other end through the side of the piston at a pointspaced from its end a distance equal to the distance between the port 38 in the cylinder and the cylinder head.

Inlet passages to the cylinders 14 are provided for by pipes 40, 40 opening into the top sides of said cylinders at points preferably nearer to the inner than the outer ends of the cylinders. ,The compressed fluid, which, as'will presently appear, is discharged into the crank case 12, is led there-- from through an outlet nipple 12 in the bottom wall of the casing to any suitable receiver (not shown) as for example, the condenser of a refrigerating apparatus.

The operation of the compressor is as follows :The rotation of the shaft 15 produces a reciprocatory movement of the yoke 25 in the crank case and of course a similar movement of the pistons :26 intheir respective cylinders. As illustrated in Fig. 1. the pistons have reached the ends of their stroke, the one, namely the one on the left hand, being at the end of its suction stroke and the other, namely the one on the right hand, being at the end of its compression stroke. The left hand piston has uncovered the inlet opening of the pipe 40 and has drawn a. charge of low pressure fluid into its cylinder, It will be noticed that each piston, during its inward or suction stroke, closes the port 36 and duringits outward or compression stroke, closes the associated inlet pipe 40. The low pressure fluid entering through the pipe 40 on the suction stroke, will be compressed as the piston moves toward the cylinder head on its compression stroke. Asthe piston approaches the outer end of its stroke, it will first close the port 38 and then will close the port 37, as shown in Fig. l. Previously to this-closing of said ports, a large part of the compressed fluid has been forced into the passageway 35. The rear end of the piston will then uncover the outlet port 36, thus providing an escape for the compressed fluid into the crank case After the piston 26 has closed the port 37 and opened the port 36, and as it approaches and reaches the end of its stroke. the passage '26 in the piston is brought to register with the port 38' in the cylinder wall and the fluid compressed at the end of the stroke of the piston is permitted to escape to the passageway 35, thus discharging all of the fluid from the cylinder and preventing the formation of a pneumatic cushion atthe end of the stroke. The relative positions of the ports at the end of the compression stroke is shown in Fig. 1.

On its back stroke, the piston first closes the auxiliary discharge port 38; then closes the outlet port 36, thereby preventing a return flow of high pressure fluid from the crank case into the passageway 35. The main discharge port 37 at this time, is still closed, but as the piston proceeds on its return stroke, said port is uncovered immediately after the outlet port 36 is closed. Such fluid as remains in the passageway 35 will be re'e'xpanded in the return or back stroke of the piston, but as the amount is small, it will be of no moment. The piston on its return or back stroke being thus closed off from the crank case, a vacuous or low pressure condition is produced therein, so

that when the piston uncovers the inlet pipe 40, a fresh charge of fluid will be drawn or sucked into the cylinder. The ports 36, 37 and 38 connecting the passageway 35 with the interior of the cylin-- der, being slots arranged transversely relative to the travel of the piston, resent comparatively large port areas wliich can be covered and uncovered in a comparatively short movement of the piston.

The many advantages of my improved compressor will be apparent to those familiar with the art. As no gears are used, the compressor will be noiseless in its operation. All the power imparted to the shaft 15 is used in the compression of the fluid operated upon and is not expended or dissipated in operating valve mechanism. Again, as the plates 13 and associated cylinders are alike, a saving of material, time and labor ishad in the machining of them, because after the work ji is once in place, identical, true cylinder piiites are bound to result.

No gear or valve shafts need be timed to the reciprocation of the piston, hence there is a saving of time and labor in the assembl Thus the improved compressor may be ma e at an extremely low cost of manufacture.

While in describing my invention, I have referred to the particular location and kind of the various ports provided, I do not wish to be limited thereto except as may be pointed out in the appended claims.

I claim as my invention:

1. Ina compressor, the combination 0 a cylinder provided with an inlet port and with longitudinally spaced outlet and discharge ports, all opening into the cylinder at its sides, the outlet port being located at the outer, and the discharge port, at the inner end of the cylinder, and a piston reciprocable in said cylinder, and adapted to cover and uncover said ports in proper timed relation.

2. In a compressor, the combination of a cylinder provided with an inlet port, and with an exhaust passageway opening into the cylinder by a port near the head of the cylinder, and by a port at the inner end of the cylinder, and a piston reciprocable in said cylinder, adapted to cover. and uncover said ports in proper timed relation;

3. In a compressor, the combination of a cylinder provided with an exhaust passageway opening into the cylinder by ports at the head and at the inner end of the cylinder, a piston reciprocable in said cylinder and adapted to cover and uncover said ports 1n. proper'timed relation, and means providing for a discharge into'said passageway from the space between the piston and the head of the cylinder after the piston has passed and closed the said head of the cylinder.

In a compressor, the combination of port at the a cylinder provided with an inlet port and with an exhaust passageway opening by ports into the cylinder at its sides, one of said ports being near the head of the cylinder, and the other port being at the inner piston reciprocable in said cylinder and adapted to cover and uncover said ports in proper timed relation, the piston being provided with a passageway opening through its end and through its side and adapted to register with said auxiliary port when the port at the head of the cylinder is closed.

5. In a compressor, the combination of a cylinder provided at one side with a longitudinally extending passageway of comparatively small cross sectional area, said passageway opening into the cylinder, through longitudinally spaced ports, one at the head of the cylinder and one at the inner end of the cylinder, said ports consisting of elongated, narrow slots extending transversely of the cylinder, and a piston reciprocablein said cylinder, adapted to cover and uncover said slots, said slots being spaced apart a distance shorter than the length of the piston.

In testimony, that I claim the foregoing as my invention I aflix my signature in the presence of two witnesses, this 28th day of December, A. D. 1916.

TORRIS H. ALFREDS.

Witnesses:

D. C. DARRENONGUE, .KARL W. DALL. 

